The proposed study takes to scale an early literacy intervention program found to be effective with middle class children wherein at risk kindergartners were provided with small group remediation and given one-to-one tutoring in first grade if they continued to need remedial services. The kindergarten intervention program significantly reduced both the number of children requiring remedial services at the beginning of first grade and the number of children who continued to experience serious reading difficulties at the end of first grade. One objective of the proposed study is to evaluate the effectiveness of the intervention programs with children living in poverty. However, in view of research documenting that well-balanced classroom instruction can, by itself, reduce the number of emergent readers requiring remedial services, the primary objective of the study is to evaluate the relative effectiveness of implementing the early intervention program just described compared with either professional development to improve the quality of classroom literacy instruction or an intervention strategy that makes use of both of these procedures. Given the costs associated with intensive reading intervention programs, it is clearly important to evaluate the extent to which classroom programs can be made more effective in reducing and/or eliminating early reading difficulties. Further, because of the amount and types of interactions classroom teachers have with their students, they are in a better position than are intervention teachers to promote the development of oral language abilities and general world knowledge, skills which are critically important to reading comprehension. The study will follow three cohorts of children longitudinally from the beginning of kindergarten until the end of second or third grade. The Baseline Cohort will be followed through periodic assessment of literacy and language skills and through observation of their kindergarten and first grade instruction, with no attempt to influence the instruction. The Implementation Cohort will be involved in one of three major treatment groups: 1) early literacy intervention services provided for at risk and poor readers, 2) professional development provided to kindergarten and first grade classroom teachers, or 3) both early intervention services and professional development for classroom teachers. This Cohort will also be followed through assessment and observation of classroom instruction. The Maintenance Cohort will be assigned to the same treatment groups as the children in the Implementation Cohort, but the ongoing professional development support will be discontinued for teachers during the year in which they have Maintenance Cohort children, allowing us to determine whether any instructional modifications evident for the Implementation Cohort are maintained. On the assumption that both the intervention programs and the Professional Development programs will prove to be effective in improving literacy outcomes for young children, we also propose to take steps to prepare for a more broadly based implementation. First, we plan to groom Instructional Leaders in each of the participating schools in order to help institutionalize the early literacy instructional practices promoted by the project and to help disseminate these practices in their own districts and beyond. Second, we will gather questionnaire and interview data from administrators and teachers on an annual basis to better understand, through the eyes of the practitioners, the strengths and weaknesses of the approach we have taken and how it might be improved to make it more useful to them. Finally, the data gathered in various components of the study will be analyzed using recently developed modeling techniques for evaluating growth over time.